A filmmaker with an eagle eye for how people behave

France's version of the Oscar is called the Cesar. Last year a movie called La Balance swept all the top categories, winning awards for best picture and best performances. It was a box office hit, too, almost outgrossing ''E.T.'' there.

Clearly, this is a movie connected with the French imagination. Yet it was written and directed by a young American named Bob Swaim, a former anthropology student with a sharp eye for details of human behavior. In keeping with both his academic background and his love of film, he researched police activity in Paris for months before beginning the picture.

It's a rough and sometimes rude movie. The plot centers on a couple of small-time offenders with connections to a major criminal operation, and on policemen who pressure them into becoming informers. The petty criminals are seen as whole human beings, if badly misguided ones. The police are seen as pragmatic professionals, on the right side but capable of morally dubious decisions.

Many of the characters are nasty, some of the situations are harrowing. But the picture never loses sight of its deeper concerns - about class conflict, the nature of loyalty, and the ethics of a police system based largely on informers. Lending more depth are heartfelt performances by Nathalie Baye and Philippe Leotard, among others.

Although filmmaker Swaim is a lifelong movie-lover, he first went to France as a would-be author, following the trail of the Hemingway crowd and the ''beat generation'' drifters. Arriving in Paris a little too late, he found the expatriate literary scene was no more. So he passed the time between anthropology classes at a cinematheque, learning to watch movies with the highly analytical mind-set French cineastes are noted for.

Deciding to make movies himself, he enrolled in a film school, training not as a director, but as a cameraman, since he wanted to master the technical side of production, and also have a good shot at getting work. After a long string of commercials and documentaries - ''they taught me how to look at people'' - he made his first feature in the intellectual French mold he learned at the cinemathequem.

While he's still proud of it, he admits it isn't the kind of picture he'd go and see. ''I had to find my own voice,'' he told me the other day during a New York visit, ''and get back to the direct, gut-level storytelling that really is my style, deep down.''

He did just that in ''La Balance,'' which never lets its thoughtful undertones get in the way of its careening plot. The key is Swaim's fascination with people, and his ability to combine the excitement of melodrama with insights gained from observation of real events and personalities. At times ''La Balance'' recalls the work of earlier French directors, most notably Jean-Pierre Melville, who also drew on Hollywood's vocabulary, although in a more stylized way. But it reflects Swaim's anthropological streak, too, which ties in with a long French tradition stretching from Jean Rouch's ethnological films to Chris Marker's dense documentaries.

''Life and experience'' are the heart of any artist's training, says Swaim, who was drawn to anthropology largely because it allows for generalists as well as specialists.''If an 18-year-old falls in love with film,'' he says, ''and spends his time in movie theaters studying fantasies, I wonder how equipped he'll be to go out and make meaningful pictures.''

His feelings are clear, despite his own years in the darkness of the cinematheque. ''Today if I had the choice of sitting in a movie theater or sitting on a park bench watching people go by,'' he says with good-natured conviction, ''I'd definitely choose the bench.'' People, not visual pyrotechnics , are the essence of movies for him. Views of working class

Among its other virtues, ''Heart Like a Wheel'' - the film biography of drag racer Shirley Muldowney - takes a refreshingly candid and uncondescending approach to working-class characters. This was a conscious aim of director Jonathan Kaplan, who says he's fed up with stereotyped views of workers as either irresponsible or brainlessly cheerful. I wish other current films treated proletariats with equal respect.

Educating Rita, for instance, is a winning and literate movie in many ways. It has a ''Pygmalion''-type plot, with an unschooled hairdresser who goes to a dissipated literature professor in hopes of improving her mind. The dialogue is sharp and snappy (if sometimes vulgar), and the performances by Michael Caine and Julie Walters are as warm as one could wish.

What makes me uncomfortable is the film's unspoken premise that working-class life isn't important, and escape should be a thinking person's goal. As her education proceeds, Rita acquires not only a new vocabulary but new interests, new clothes, new friends - and the old are tossed aside as so much chaff. To his credit, director Lewis Gilbert takes care to give us glimpses of life among the workers, showing both contentment and sorrow. Also, the tipsy Caine character is no ringing endorsement for academia. But this isn't enough to balance Rita's manic joy at severing her roots and plunging with uncritical zeal into bourgeois heaven.

Will there be a sequel - ''Rita Goes to Grad School'' - in which our heroine learns the middle class isn't all its cracked up to be? Stay tuned.

Similar problems dog Experience Preferred . . . But Not Essential, directed by Peter Duffel. The protagonist is a student with a summer job at a Welsh hotel , where she first encounters work and romance - and plain people who aren't on a lark but labor with their hands all the time. Though the performances are deft, the movie often seems to be slumming, peering at colorful types who are fun to visit but not the kind you'd want to live with. At the end, the heroine goes home, and there's hardly a shrug for the less-advantaged folks she's left behind. It's not the worst sin a film can commit, but it further limits an already minor movie.